Solve by substitution:
3x-2y=14
y=5x
solve by substitution
x-2y=-2
y=2x+4
solve by elimination
x+2y=-7
x-5y=7
worth 10 points! aka show work: )

1)
3x-2y=14
y=5x

So we plug in y=5x into 3x-2y=14

We get:

3x-2(5x)=14
3x -10x=14
-7x=14
x=-2

So we found x, now we need to find y. We can simply plug in x into the equation and get y.

y=5x
y=5(-2)
y=-10

So your answer will be (-2,-10).

2) 
x-2y= -2
y= 2x+4

Once again plug in y=2x+4 into x-2y=-2

x-2(2x+4) = -2
x-4x-8=-2
-3x-8=-2
-3x = 6
x= -2

Now we plug back in x and solve for y :)

y=2x+4
y=2(-2)+4
y=-4+4
y=0

So our solution would be (-2,0).

3)
x+2y=-7
x-5y=7

Multiply the second equation by -1

-x+5y=-7

Now add that equation with the other one:

   x+2y=-7
+
   -x+5y=-7

7y=-14
y=-2

Now plug in y=-2 and solve for x

x+2y=-7
x+2(-2)=-7
x+(-4)=-7
x-4=-7
x=-3

So your solution would be (-3,-2).

1)



We know y's value. Let's plug it in the equation.



Divide both sides by -7.



Now we have x's value. Let's plug it in the equation to find y.



Solution,

(-2, -10)

2)


Again we have y's value. Let's plug and solve.



Now we have x's value let's solve for y.



Solution,

(-2, 0)

3)



Let's first multiply the first equation by -1



Then let's add these new equation and the second equation.



Now we have y's value let's plug it and solve for x.



Solution,

(-3, -2)